Dock crane

ABSTRACT

The boom of a dock crane is pivoted to a trolley which is displaceably mounted on a mobile frame on the wharf. A support member, such as another trolley or a strut, supports the tackle for the boom intermediate the tackle and the frame. A cable connects the support member to the boom supporting trolley and guide pulleys for the cable are so mounted that the support member is displaced simultaneously in the same direction and at the same speed as the boom supporting trolley and to transmit to the frame the tilting force due to the weight of the boom and any load thereon.

llnited States Patent r 1 Grandin DOCK CRANE [75] Inventor: Daniel Grandin, Fontenay-aux- Roses, France [73] Assignee: Fives Lille-Call, Paris, France [22] Filed: Feb. 4, 1972 [21] Appl. No.: 223,660

[30] Foreign Application Priority Data Feb. 8, 1971 France ..7104063 June 11, 1971 France ..7121237 [52] 0.8. CI ..2l4/l4, 212/49 [51] int. Cl. ..B65g 63/00 [58] Field of Search ..214/l4, 15 E, 142, 2l4/l27;212/48,49

[56] References Cited UNITED STATES PATENTS 1,442,521 1/1923 Case ..214/14 X 1,991,652 2/1935 Bean ..214/14 X 3,146,898

9/1964 Kersting "214/ 14 May 29, 11973 FOREIGN PATENTS OR APPLICATIONS 12/1932 Germany ..2l4/l4 1/1954 France ..2l2/48 Primary ExaminerGerald M. Forlenza Assistant Examiner-Frank E. Werner Attorney-Kurt Kelman [57] ABSTRACT The boom of a dock crane is pivoted to a trolley which is displaceably mounted on a mobile frame on the wharf. A support member, such as another trolley or a strut, supports the tackle for the boom intermediate the tackle and the frame. A cable connects the support member to the boom supporting trolley and guide pulleys for the cable are so mounted that the support member is displaced simultaneously in the same direction and at the same speed as the boom supporting trolley and to transmit to the frame the tilting force due to the weight of the boom and any load thereon.

14 Claims, 5 Drawing Figures DOCK CRANE The present invention relates to improvements in apparatus for loading and unloading bulk material into and from the hold of a ship.

Conventional dock cranes comprise a mobile frame mounted on a wharf or pier for movement in a first direction along the dock and a pivotal boom, jib or swingable arm extending in a second direction perpendicular to the direction of movement of the mobile frame. A trolley is displaceably mounted on the frame for movement thereon in the second direction and one end of the pivotal boom is pivotally mounted on the trolley for pivoting about a horizontal axis extending in the first direction, i.e., in a plane extending in the second direction. Conveyor means for receiving and transporting the bulk material is carried by the other end of the pivotal boom, and means, such as a tackle, is provided for raising and lowering the pivotal boom by pivoting the boom about the horizontal axis. In this manner, the conveyor means may be advanced and retracted, as well as lowered into and raised from a hold of a docked ship.

Generally, the windlass for the tackle has been carried by the trolley which supports the boom. To take up or absorb the tilting force due to the weight of the boom and any load thereon, it has been necessary either to mount a balancing counterweight on an arm integral with the trolley or to give the trolley sufficient length to counterbalance this force. Such apparatus is cumbersome and excessively large, particularly when the crane is designed to handle heavy loads.

It has also been proposed to mount the windlass directly on the frame of the crane. In this case, however, the pressure exerted by the boom upon its supporting trolley must be absorbed entirely by the drive mechanism for the trolley and, in addition, each displacement of the trolley is accompanied by a variation in the inclination of the boom unless complicated synchronization mechanism between the trolley drive and the windlass is provided.

It is the primary object of this invention to avoid the above and other disadvantages of conventional dock cranes. This is accomplished in accordance with the invention by mounting a support member, such as a second trolley or a strut, for the pivotal boom raising and lowering means for supporting this means on the frame. A flexible elongated coupling element, such as a cable, chain or band, connects the support member to the boom supporting trolley and guide means, such as a set of guide pulleys or drums, for the flexible coupling element are so mounted on the mobile frame between the support member and the trolley that the support member is displaced simultaneously in the same direction and at the same speed as the trolley, and to transmit to the frame the tilting force due to the weight of the boom and any load thereon.

According to one featureof the present invention, the drive for the trolley comprises two gears mounted on the trolley on either side thereof, two racks fixedly mounted on the frame, the gears meshing with the racks and the racks extending in the second direction. A torsion shaft extends perpendicularly to the second direction and interconnects the gears. A motor may be provided for rotating the gears. t

In accordance with another feature of this invention, a counterweight balances a part of the weight of the pivotal boom, a cable whereon the counterweight is suspended is affixed to the pivotal boom, and a guide pulley for the cable is mounted on the support member. Preferably, the other end of the cable is affixed to the trolley, and the path of the cable is parallel to that of the flexible elongated coupling element connecting the support member to the trolley.

Where the boom raising and lowering means comprises a windlass and tackle, a safety device may be provided including a counterweight attached to the tackle, a blocking or braking means for holding the counterweight in a fixed position relative to the windlass under normal operating conditions, a control for inactivating the blocking means in response to a measured load on the boom when the operating conditions are not normal, and a drive responsive to the control to displace the counterweight downwardly when the measured load is lower than a predetermined, normal load value and thus to raise the boom slightly correspondingly to the lowering of the counterweight. This safety device control may include a dynamometer mounted on the flexible elongated coupling element to measure the tension thereof.

The above and other objects, advantages and features of the present invention will become more apparent from the following detailed description of two now preferred embodiments thereof, taken in conjunction with the accompanying drawing wherein FIG. 1 is a schematic side elevational view of one embodiment of the apparatus according to this invention, with the boom in extended position;

FIG. 2 is a similar view, with the beam in retracted position, the boom being shown raised in full lines and lowered in dot-dash lines;

FIG. 3 schematically shows the system for raising and lowering the boom;

FIG. 4 is a view similar to that of FIG. I of another embodiment; and

FIG. 5 is a view similar to that of FIG. 2 of the embodiment of FIG. 4.

Referring now to the drawing, wherein like reference numerals designate like parts in all figures, FIGS. 1 and 2 show an apparatus for loading or unloading bulk material into, or from, the hold of a ship, which comprises essentially a mobile frame 1 whose four legs 2 are mounted on wheels or rollers 3 which run on rails 4 on wharf or pier 5 substantially parallel to the dock. A boom 6 is mounted on frame 1, one end of the boom being pivotal about shaft 15 for raising and lowering the boom in a vertical plane perpendicular to the frame, as indicated by the double-headed arrow in FIG. 1, while the other end of boom 5 has suspended therefrom a bulk material handling and conveying device 7 for collecting and/or depositing the bulk material and for transporting the same, which includes bucket conveyors 31.

The system for raising and lowering the boom, as well as for advancing and retracting it, is more fully illustrated in FIG. 3 and includes a first trolley and a second trolley 9, both supported on mobile frame 1, the first trolley having the pivoting shaft 15 for the one boom end mounted thereon while the second trolley has the windlass 10 for raising and lowering the boom mounted thereon.

The first trolley 8 runs on wheels or rollers 8a on rails 11 which are mounted on two girders 12 extending transversely of the frame and perpendicularly to rails 4 along which the frame moves along the dock. The secnd trolley 9 runs on wheels or rollers 9a on rails 16 similarly mounted on two girders 17 parallel to rails 11 and girders 12.

The first trolley may be displaced or driven along rails 11 by suitable motor means (not shown) operatively connected to two gears 13 mounted on respective sides of the trolley 8 and entrained by the motor means. The gears 13 engage the respective racks 14 mounted on transverse girders 12. The two gears are coupled by a torsion shaft of large cross section so as to prevent any substantial relative rotation of the gears and to permit the moment of force exerted by the boom upon the trolley 8 to be absorbed when the boom is subjected to lateral pressures due, for example, to wind or the impact of the device 7 or the bucket conveyors 31 on a fixed part of the ship. Braking means (not shown) permit the trolley 8 to remain fixed in any selected position.

A conventional tackle comprising rope or cable and block 20 connects the Windlass 10 to the other boom end for pivoting the boom about shaft 15, one end of the rope being affixed to the Windlass while a counterweight 21 is affixed to the other rope end. The counterweight is integral with a vertically mobile carriage carrying gear 22 meshing with vertical rack 23 on a vertical girder 24 which extends from trolley 9 and forms a part thereof. The gear 22 is motor driven but its movement is normally impeded by a braking means (not shown). The mass of the counterweight is chosen intermediate that required to balance the weight of the boom and the charge carried thereby in the working and retracted positions.

As clearly shown in FIG. 3, the two trolleys 8 and 9 are interconnected or coupled together by a rope or cable 25 having one end affixed to the one trolley and the other end affixed to the other trolley, the rope 25 being trained over three guide pulleys 26 so that the rope is held under tension by the forces exerted upon the trolley by boom 6, the rope coupling being such that the two trolleys are always displaced along their rails in the same direction and at the same speed.

It will be noted that the trolley assembly does not have the tendency of being displaced under the force of the weight of the boom and its load because the horizontal components of this force are equal and opposed to each other. Therefore, the brakes and the drive mechanism for trolley 8 need to absorb only the exterior horizontal forces parallel to the direction of displacement of the trolley to which the boom may be subjected.

Depending on the size of the forces, i.e., the weights and the capacity of the apparatus, a single rope or cable may be used to couple the first and second trolleys, or a plurality of parallel ropes or cables may be used for this purpose. If desired, a chain or chains may be used instead of ropes or cables. Also, instead of using a set of parallel cables trained over respective sets of guide pulleys, a metallic band or a reinforced strap trained over guide drums may be used.

To relieve the Windlass 10, a portion of its load is absorbed by counterweight 27 which is carried by rope or cable 28 whose one end is affixed to boom 6 while its other end is affixed to the first trolley 8, the cable 28 passing over guide pulley 29 mounted on second trolley 9 and then being trained over a series of guide pulleys 30 mounted on support frame 1 so that the course of cable 28 is parallel to the course of cable 25 coupling together the trolleys 8 and 9. Depending on the weight of the counterweight, a single cable or a set of parallel cables will be used to support the counterweight.

In a conventional manner (not shown), the bulk material handling device 7 is suspended from the boom 6 by means of a universal coupling which permits the device to remain in a vertical position regardless of the angle of inclination of boom 6 and to oscillate, for instance, during the displacement of the apparatus without exerting a torsional force on the boom. If desired, shock absorbing means may be provided to brake the oscillations of the device 7.

The device for collecting and/or depositing the bulk material and for transporting the same comprises two parallel bucket conveyors 31, 31 mounted on the end of the device 7 remote from the end thereof which is mounted on the boom 6. When the boom lowers the bucket conveyors into the hold 18 of a ship, the bucket conveyors will either unload bulk material into the hold, when the apparatus is used for loading the ship, or will take up the bulk material in the hold, when the apparatus is used for unloading the ship. As is known and not illustrated herein, the bulk material is transported to or from the bucket conveyors 31 by suitable conveyors mounted in device 7 and in boom 6. The conveyor in boom 6 transports the unloaded bulk material to a hopper 32 mounted below the one end of boom 6 to receive the material and discharge it to a conveyor band 33 mounted on the frame 1 below the hopper, a downwardly inclined further conveyor band 34 receiving the material from the discharge end of the conveyor band 33 and transporting it to a final conveyor band 32 mounted on the pier and extending in a longitudinal direction to take the bulk material away from the apparatus.

As shown in H0. 2, when the apparatus is in the inoperative position, the two trolleys 8 and 9 are retracted. During loading or unloading, the trolleys are advanced by driving the gear 13 of the first trolley so as to place the device 7 into alignment with the hold of the ship and the boom is then lowered so that the bucket conveyors 31 enter into the hold.

The entire area of the hold 18 may be covered during operations by displacing the trolleys 8 and 9 transversely along their rails 11 and 16 so as to move along the entire width of the hold and by displacing the support frame 1 along the rails 4 to move along the entire length of the hold. Thus, the entire bulk material may be loaded or unloaded.

The assembly constituted by counterweight 21, gear 22 and its motor and brake forms a safety device which permits the rapid rising of the boom when the bucket conveyors push against the walls or bottom of the hold. in this case, a dynamometric device 36 mounted on cable 25, which couples the two trolleys 8 and 9 together, senses a reduction of the force exerted by the boom 6 upon the trolleys and immediately causes the Windlass 10 to cease operation, the dynamometric control of the Windlass being accompanied simultaneously by unblocking of the brakes of gear 22 and actuation of the motor drive therefor to displace the counterweight 21 downwardly. As the counterweight 21 descends, the boom will be rapidly raised a little and sufficiently to limit any possible damage caused by the impact of the bucket conveyors on the ship walls. Thereupon, the counterweight 21 is returned to its initial position.

Since the two trolleys 8 and 9 are coupled for simultaneous movement, it would be possible, of course, to drive the second trolley, instead of the first trolley, without any change in the function of the apparatus. However, the first trolley should always have a means for absorbing the lateral forces exerted by the boom which, by the way, may be separate from the gear-andrack drive, as hereinabove described. Also, the drive means for the trolleys may take any suitable form, for instance a system of winch and cables. Furthermore, the device for collecting and/or depositing the bulk material may take any desired form, as will be obvious to those skilled in the art. For instance, a bucket elevator may be used for directly collecting and transporting the bulk material from the hold of the ship.

In the embodiment of FIGS. 4 and 5, the mobile frame 100 again has four legs mounted on wheels or rollers 103 running on rails 4 along the wharf. A boom 116 is mounted on frame 100, one end of the boom being pivotally mounted on trolley 103 for raising and lowering the boom while the other end of the boom has universally suspended therefrom a bulk material handling device 117 which carries a device for collecting and/r depositing bulk material, including a pair of bucket conveyors 131.

In this embodiment, the single trolley 108, similarly to trolley 8 of the first described embodiment, runs on wheels or rollers on rails 111 which are mounted on two girders 112 extending transversely of the frame 100 and perpendicularly to rails 4 along which the frame moves along the dock. The trolley may be displaced or driven along rails 111 by any suitable drive means (not shown), such as the gear-and-rack drive of the first-described embodiment.

The trolley 108 has mounted thereon a strut or truss 137 whose one end is pivotal about a horizontal axle carried by the trolley and whose other end is connected to the trolley by a rope or cable 125 which is trained over guide pulleys 126 mounted on frame 100. This coupling causes the strut 137 to be displaced in unison with the carriage without changing its angular position in respect thereto, as will be noted from the respective advanced and retracted positions illustrated in FIGS. 1 and 5.

The strut or truss 137 consists of two girders disposed on either side of the boom 106 and interconnected by a cross bar or brace at the upper ends thereof.

A conventional tackle connects the windlass 110 mounted on trolley 108 to the other boom end for pivoting the boom, one of the tackle blocks being mounted on the upper end of the strut 137 while the other block thereof is close to the boom end.

The length of the cable 125 is so selected as to give the strut 137 the orientation most favorable for the absorption of the forces to which it is subjected.

Again, the collected bulk material is discharged into a hopper 132 whence it is discharged onto conveyor band 133, transported to another hopper 132 which discharges it onto another conveyor for discharge into trucks 135 on the pier. It will be useful (although not shown) to provide this embodiment with the same type of counterweight relief for the windlass and the safety device as described in connection with the other embodiment.

I claim:

1. An apparatus for loading and unloading bulk material into and from the hold of a ship, comprising the combination of l. a mobile frame mounted on a wharf for movement in a first direction,

2. a pivotal boom extending in a second direction perpendicular to the direction of movement of the mobile frame,

3. a trolley mounted displaceably on the frame for movement thereon in the second direction, (a) one end of the pivotal boom being pivotally mounted on the trolley for pivoting about a horizontal axis,

4. means for receiving and transporting the bulk material carried by the other end of the pivotal boom,

5. means for raising and lowering the pivotal boom by pivoting the boom about the horizontal axis,

6. a support member for the pivotal boom raising and lowering means intermediate said means and the mobile frame for supporting the means on the frame,

7. a flexible elongated coupling element connecting the support member to the trolley, and

8. guide means for the flexible coupling element so mounted on the mobile frame between the support member and the trolley that the support member is displaced simultaneously in the same direction and at the same speed as the trolley, and to transmit to the frame the tilting force due to the weight of the boom and any load thereon.

2. The apparatus of claim 1, wherein the means for raising and lowering the pivotal boom comprises a windlass and a tackle between the windlass and the other end of the boom, the windlass being mounted above the trolley.

3. The apparatus of claim 2, wherein the support member is a second trolley mounted displaceably on the frame for movement thereon in the second direction.

4. The apparatus of claim 3, wherein the windlass is mounted on the second trolley.

5. The apparatus of claim 1, further comprising drive means for displacing the trolley.

6. The apparatus of claim 1, wherein the support member is a strut having one end supported on the trolley and the other end connected to the trolley by the flexible elongated coupling element.

7. The apparatus of claim 6, wherein the one end of the strut is pivoted on the trolley.

3. The apparatus of claim 6, wherein the means for raising and lowering the pivotal boom comprises a windlass mounted on the trolley and a tackle between the windlass and the other end of the boom, the tackle being connected to the other end of the strut.

9. The apparatus of claim 1, further comprising two gears mounted on the trolley on either side thereof, two racks fixedly mounted on the frame, the gears meshing with the racks and the racks extending in the second direction, and a torsion shaft extending perpendicularly to the second direction and interconnecting the two gears.

10. The apparatus of claim 1, further comprising a counterweight for balancing a part of the weight of the pivotal boom, a cable whereon the counterweight is suspended and having one end affixed to the pivotal boom, and a guide pulley for the cable mounted on the support member.

11. The apparatus of claim 10, wherein the other end of the cable supporting the counterweight is affixed to the trolley, and the path of the cable is parallel to that of the flexible elongated coupling element connecting the support member to the trolley.

12. The apparatus of claim 1, wherein the means for raising and lowering the pivotal boom comprises a Windlass and a tackle between the Windlass and the other end of the boom, and further comprising a safety device including a counterweight attached to the tackle, a blocking means for holding the counterweight in a fixed position relative to the windlass under normal operating conditions, a control for inactivating the blocking means in response to a measured load on the boom when the operating conditions are not normal, and a drive means responsive to the control to displace the counterweight downwardly when the measured load is lower than a predetermined, normal value and thus to raise the boom correspondingly.

13. The apparatus of claim 12, wherein the drive means comprises a gear carried by the counterweight and a rack mounted at a fixed distance from the windlass, the gear meshing with the rack, and the blocking means normally preventing rotation of the gear.

14. The apparatus of claim 12, wherein the control comprises a dynamometric device mounted on' the flexible elongated coupling element. 

1. An apparatus for loading and unloading bulk material into and from the hold of a ship, comprising the combination of
 1. a mobile frame mounted on a wharf for movement in a first direction,
 2. a pivotal boom extending in a second direction perpendicular to the direction of movement of the mobile frame,
 3. a trolley mounted displaceably on the frame for movement thereon in the second direction, (a) one end of the pivotal boom being pivotally mounted on the trolley for pivoting about a horizontal axis,
 4. means for receiving and transporting the bulk material carried by the other end of the pivotal boom,
 5. means for raising and lowering the pivotal boom by pivoting the boom about the horizontal axis,
 6. a support member for the pivotal boom raising and lowering means intermediate said means and the mobile frame for supporting the means on the frame,
 7. a flexible elongated coupling element connecting the support member to the trolley, and
 8. guide means for the flexible coupling element so mounted on the mobile frame between the support member and the trolley that the support member is displaced simultaneously in the same direction and at the same speed as the trolley, and to transmit to the frame the tilting force due to the weight of the boom and any load thereon.
 2. a pivotal boom extending in a second direction perpendicular to the direction of movement of the mobile frame,
 2. The apparatus of claim 1, wherein the means for raising and lowering the pivotal boom comprises a windlass and a tackle between the windlass and the other end of the boom, the windlass being mounted above the trolley.
 3. The apparatus of claim 2, wherein the support member is a second trolley mounted displaceably on the frame for movement thereon in the second direction.
 3. a trolley mounted displaceably on the frame for movement thereon in the second direction, (a) one end of the pivotal boom being pivotally mounted on the trolley for pivoting about a horizontal axis,
 4. means for receiving and transporting the bulk material carried by the other end of the pivotal boom,
 4. The apparatus of claim 3, wherein the windlass is mounted on the second trolley.
 5. means for raising and lowering the pivotal boom by pivoting the boom about the horizontal axis,
 5. The apparatus of claim 1, further comprising drive means for displacing the trolley.
 6. a support member for the pivotal boom raising and lowering means intermediate said means and the mobile frame for supporting the means on the frame,
 6. The apparatus of claim 1, wherein the support member is a strut having one end supported on the trolley and the other end connected to the trolley by the flexible elongated coupling element.
 7. The apparatus of claim 6, wherein the one end of the strut is pivoted on the trolley.
 7. a flexible elongated coupling element connecting the support member to the trolley, and
 8. guide means for the flexible coupling element so mounted on the mobile frame between the support member and the trolley that the support member is displaced simultaneously in the same direction and at the same speed as the trolley, and to transmit to the frame the tilting force due to the weight of the boom and any load thereon.
 8. The apparatus of claim 6, wherein the means for raising and lowering the pivotal boom comprises a windlass mounted on the trolley and a tackle between the windlass and the other end of the boom, the tackle being connected to the other end of the strut.
 9. The apparatus of claim 1, further comprising two gears mounted on the trolley on either side thereof, two racks fixedly mounted on the frame, the gears meshing with the racks and the racks extending in the second direction, and a torsion shaft extending perpendicularly to the second direction and interconnecting the two gears.
 10. The apparatus of claim 1, further comprising a counterweight for balancing a part of the weight of the pivotal boom, a cable whereon the counterweight is suspended and having one end affixed to the pivotal boom, and a guide pulley for the cable mounted on the support member.
 11. The apparatus of claim 10, wherein the other end of the cable supporting the counterweight is affixed to the trolley, and the path of the cable is parallel to that of the flexible elongated coupling element connecting the support member to the trolley.
 12. The apparatus of claim 1, wherein the means for raising and lowering the pivotal boom comprises a windlass and a tackle between the windlass and the other end of the boom, and further comprising a safety device including a counterweight attached to the tackle, a blocking means for holding the counterweight in a fixed position relative to the windlass under normal operating conditions, a control for inactivating the blocking means in response to a measured load on the boom when the operating conditions are not normal, and a drive means responsive to the control to displace the counterweight downwardly when the measured load is lower than a predetermined, normal value and thus to raise the boom correspondingly.
 13. The apparatus of claim 12, wherein the drive means comprises a gear carried by the counterweight and a rack mounted at a fixed distance from the windlass, the gear meshing with the rack, and the blocking means normally preventing rotation of the gear.
 14. The apparatus of claim 12, wherein the control comprises a dynamometric device mounted on the flexible elongated coupling element. 